diff --git a/sprout/algorithm/fixed/clamp_range_copy.hpp b/sprout/algorithm/fixed/clamp_range_copy.hpp
index 3682807d..6d467ea1 100644
--- a/sprout/algorithm/fixed/clamp_range_copy.hpp
+++ b/sprout/algorithm/fixed/clamp_range_copy.hpp
@@ -75,7 +75,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			clamp_range_copy_impl(
-				InputIterator, InputIterator, Result const& result,
+				InputIterator const&, InputIterator const&, Result const& result,
 				typename std::iterator_traits<InputIterator>::value_type const&,
 				typename std::iterator_traits<InputIterator>::value_type const&,
 				Compare,
diff --git a/sprout/algorithm/fixed/copy.hpp b/sprout/algorithm/fixed/copy.hpp
index 20635ffb..dcf7d131 100644
--- a/sprout/algorithm/fixed/copy.hpp
+++ b/sprout/algorithm/fixed/copy.hpp
@@ -66,7 +66,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			copy_impl(
-				InputIterator, InputIterator, Result const& result,
+				InputIterator const&, InputIterator const&, Result const& result,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
 				)
diff --git a/sprout/algorithm/fixed/copy_until.hpp b/sprout/algorithm/fixed/copy_until.hpp
index bdb4e7c1..e65c262b 100644
--- a/sprout/algorithm/fixed/copy_until.hpp
+++ b/sprout/algorithm/fixed/copy_until.hpp
@@ -43,7 +43,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			copy_until_impl(
-				InputIterator, InputIterator, Result const& result, Predicate,
+				InputIterator const&, InputIterator const&, Result const& result, Predicate,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
 				)
diff --git a/sprout/algorithm/fixed/copy_while.hpp b/sprout/algorithm/fixed/copy_while.hpp
index 7f486f72..5b8bbc75 100644
--- a/sprout/algorithm/fixed/copy_while.hpp
+++ b/sprout/algorithm/fixed/copy_while.hpp
@@ -42,7 +42,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			copy_while_impl(
-				InputIterator, InputIterator, Result const& result, Predicate,
+				InputIterator const&, InputIterator const&, Result const& result, Predicate,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
 				)
diff --git a/sprout/algorithm/fixed/replace_copy.hpp b/sprout/algorithm/fixed/replace_copy.hpp
index 41009cb9..07cf1174 100644
--- a/sprout/algorithm/fixed/replace_copy.hpp
+++ b/sprout/algorithm/fixed/replace_copy.hpp
@@ -69,7 +69,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			replace_copy_impl(
-				InputIterator, InputIterator,
+				InputIterator const&, InputIterator const&,
 				Result const& result, T const&, T const&,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
diff --git a/sprout/algorithm/fixed/replace_copy_if.hpp b/sprout/algorithm/fixed/replace_copy_if.hpp
index ab65579b..c3f6fccd 100644
--- a/sprout/algorithm/fixed/replace_copy_if.hpp
+++ b/sprout/algorithm/fixed/replace_copy_if.hpp
@@ -68,7 +68,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			replace_copy_if_impl(
-				InputIterator, InputIterator,
+				InputIterator const&, InputIterator const&,
 				Result const& result, Predicate, T const&,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
diff --git a/sprout/algorithm/fixed/rotate_copy.hpp b/sprout/algorithm/fixed/rotate_copy.hpp
index ef4fdb06..b20b7ad7 100644
--- a/sprout/algorithm/fixed/rotate_copy.hpp
+++ b/sprout/algorithm/fixed/rotate_copy.hpp
@@ -75,7 +75,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			rotate_copy_impl_1(
-				ForwardIterator, ForwardIterator,
+				ForwardIterator const&, ForwardIterator const&,
 				Result const& result,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
@@ -106,8 +106,8 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			rotate_copy_impl(
-				ForwardIterator, ForwardIterator,
-				ForwardIterator, ForwardIterator,
+				ForwardIterator const&, ForwardIterator const&,
+				ForwardIterator const&, ForwardIterator const&,
 				Result const& result,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
diff --git a/sprout/algorithm/fixed/swap_element_copy.hpp b/sprout/algorithm/fixed/swap_element_copy.hpp
index bd9bf299..2e81f779 100644
--- a/sprout/algorithm/fixed/swap_element_copy.hpp
+++ b/sprout/algorithm/fixed/swap_element_copy.hpp
@@ -76,9 +76,9 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			swap_element_copy_impl(
-				ForwardIterator, ForwardIterator,
+				ForwardIterator const&, ForwardIterator const&,
 				Result const& result,
-				ForwardIterator, ForwardIterator,
+				ForwardIterator const&, ForwardIterator const&,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
 				)
diff --git a/sprout/algorithm/fixed/transform.hpp b/sprout/algorithm/fixed/transform.hpp
index eadb6207..9dca624f 100644
--- a/sprout/algorithm/fixed/transform.hpp
+++ b/sprout/algorithm/fixed/transform.hpp
@@ -70,7 +70,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			transform_impl(
-				InputIterator, InputIterator,
+				InputIterator const&, InputIterator const&,
 				Result const& result, UnaryOperation,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
diff --git a/sprout/algorithm/string/join.hpp b/sprout/algorithm/string/join.hpp
index f18cfcf6..92931a1b 100644
--- a/sprout/algorithm/string/join.hpp
+++ b/sprout/algorithm/string/join.hpp
@@ -173,7 +173,7 @@ namespace sprout {
 				Result
 			>::type join_impl_1(
 				ContIterator, ContIterator,
-				InputIterator, InputIterator,
+				InputIterator const&, InputIterator const&,
 				Args const&... args
 				)
 			{
@@ -355,7 +355,7 @@ namespace sprout {
 				ContIterator, ContIterator,
 				SepIterator, SepIterator,
 				bool,
-				InputIterator, InputIterator,
+				InputIterator const&, InputIterator const&,
 				Args const&... args
 				)
 			{
diff --git a/sprout/checksum/md5.hpp b/sprout/checksum/md5.hpp
index bf17fc2d..14b744b1 100644
--- a/sprout/checksum/md5.hpp
+++ b/sprout/checksum/md5.hpp
@@ -309,7 +309,7 @@ namespace sprout {
 				);
 		}
 		template<typename InputIterator>
-		SPROUT_CONSTEXPR md5 const process_block_impl(InputIterator first, InputIterator last) const {
+		SPROUT_CONSTEXPR md5 const process_block_impl(InputIterator const& first, InputIterator const& last) const {
 			return first == last ? *this
 				: c_process_byte(*first).process_block_impl(sprout::next(first), last)
 				;
@@ -362,7 +362,7 @@ namespace sprout {
 			block_.assign(0);
 		}
 		template<typename InputIterator>
-		SPROUT_CXX14_CONSTEXPR void process_block_impl(InputIterator first, InputIterator last) {
+		SPROUT_CXX14_CONSTEXPR void process_block_impl(InputIterator const& first, InputIterator const& last) {
 			for (; first != last; ++first) {
 				process_byte(*first);
 			}
diff --git a/sprout/checksum/sha1.hpp b/sprout/checksum/sha1.hpp
index ba67fb68..53e046b0 100644
--- a/sprout/checksum/sha1.hpp
+++ b/sprout/checksum/sha1.hpp
@@ -163,7 +163,7 @@ namespace sprout {
 		}
 		template<int D = 16, typename InputIterator, typename... Args, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
 		SPROUT_CONSTEXPR typename std::enable_if<sizeof...(Args) == 64, sha1 const>::type
-		process_block_impl(InputIterator first, InputIterator last, Args... args) const {
+		process_block_impl(InputIterator const& first, InputIterator const& last, Args... args) const {
 			return first == last ? process<D + 1>(
 					h_,
 					sprout::make_array<std::uint8_t>(args...),
@@ -182,12 +182,12 @@ namespace sprout {
 		}
 		template<int D = 16, typename InputIterator, typename... Args, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
 		SPROUT_CONSTEXPR typename std::enable_if<sizeof...(Args) == 64, sha1 const>::type
-		process_block_impl(InputIterator, InputIterator, Args...) const {
+		process_block_impl(InputIterator const&, InputIterator const&, Args...) const {
 			return sprout::throw_recursive_function_template_instantiation_exeeded();
 		}
 		template<int D = 16, typename InputIterator, typename... Args, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
 		SPROUT_CONSTEXPR typename std::enable_if<sizeof...(Args) != 64, sha1 const>::type
-		process_block_impl(InputIterator first, InputIterator last, Args... args) const {
+		process_block_impl(InputIterator const& first, InputIterator const& last, Args... args) const {
 			return first == last ? process<D + 1>(
 					h_,
 					sprout::get_internal(sprout::range::fixed::copy(sprout::make_array<std::uint8_t>(args...), sprout::sub(block_, block_byte_index_))),
@@ -208,7 +208,7 @@ namespace sprout {
 		}
 		template<int D = 16, typename InputIterator, typename... Args, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
 		SPROUT_CONSTEXPR typename std::enable_if<sizeof...(Args) != 64, sha1 const>::type
-		process_block_impl(InputIterator, InputIterator, Args...) const {
+		process_block_impl(InputIterator const&, InputIterator const&, Args...) const {
 			return sprout::throw_recursive_function_template_instantiation_exeeded();
 		}
 #else
@@ -273,7 +273,7 @@ namespace sprout {
 		}
 		template<typename InputIterator, typename... Args>
 		SPROUT_CONSTEXPR typename std::enable_if<sizeof...(Args) == 64, sha1 const>::type
-		process_block_impl(InputIterator first, InputIterator last, Args... args) const {
+		process_block_impl(InputIterator const& first, InputIterator const& last, Args... args) const {
 			return first == last ? process(
 					h_,
 					sprout::make_array<std::uint8_t>(args...),
@@ -290,7 +290,7 @@ namespace sprout {
 		}
 		template<typename InputIterator, typename... Args>
 		SPROUT_CONSTEXPR typename std::enable_if<sizeof...(Args) != 64, sha1 const>::type
-		process_block_impl(InputIterator first, InputIterator last, Args... args) const {
+		process_block_impl(InputIterator const& first, InputIterator const& last, Args... args) const {
 			return first == last ? process(
 					h_,
 					sprout::get_internal(sprout::range::fixed::copy(sprout::make_array<std::uint8_t>(args...), sprout::sub(block_, block_byte_index_))),
diff --git a/sprout/checksum/sum.hpp b/sprout/checksum/sum.hpp
index a730d75e..50a322e6 100644
--- a/sprout/checksum/sum.hpp
+++ b/sprout/checksum/sum.hpp
@@ -44,7 +44,7 @@ namespace sprout {
 		sum_type sum_;
 	private:
 		template<typename InputIterator>
-		SPROUT_CONSTEXPR sum_type calc_sum(InputIterator first, InputIterator last) const {
+		SPROUT_CONSTEXPR sum_type calc_sum(InputIterator const& first, InputIterator const& last) const {
 			return sprout::accumulate(
 				sprout::make_bytes_iterator(first),
 				sprout::make_bytes_iterator(last),
diff --git a/sprout/checksum/xor.hpp b/sprout/checksum/xor.hpp
index e7b29152..f644f0fb 100644
--- a/sprout/checksum/xor.hpp
+++ b/sprout/checksum/xor.hpp
@@ -33,7 +33,7 @@ namespace sprout {
 		sum_type sum_;
 	private:
 		template<typename InputIterator>
-		SPROUT_CONSTEXPR sum_type calc_sum(InputIterator first, InputIterator last) const {
+		SPROUT_CONSTEXPR sum_type calc_sum(InputIterator const& first, InputIterator const& last) const {
 			return sprout::accumulate(
 				sprout::make_bytes_iterator(first),
 				sprout::make_bytes_iterator(last),
diff --git a/sprout/numeric/dft/fixed/amplitude_spectrum.hpp b/sprout/numeric/dft/fixed/amplitude_spectrum.hpp
index a7daea68..65bfd9ab 100644
--- a/sprout/numeric/dft/fixed/amplitude_spectrum.hpp
+++ b/sprout/numeric/dft/fixed/amplitude_spectrum.hpp
@@ -68,7 +68,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			amplitude_spectrum_impl(
-				InputIterator, InputIterator, Result const& result,
+				InputIterator const&, InputIterator const&, Result const& result,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
 				)
diff --git a/sprout/numeric/dft/fixed/phase_spectrum.hpp b/sprout/numeric/dft/fixed/phase_spectrum.hpp
index 0b1a53e7..ac022d12 100644
--- a/sprout/numeric/dft/fixed/phase_spectrum.hpp
+++ b/sprout/numeric/dft/fixed/phase_spectrum.hpp
@@ -68,7 +68,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			phase_spectrum_impl(
-				InputIterator, InputIterator, Result const& result,
+				InputIterator const&, InputIterator const&, Result const& result,
 				typename sprout::container_traits<Result>::size_type,
 				Args const&... args
 				)
diff --git a/sprout/numeric/fixed/adjacent_difference.hpp b/sprout/numeric/fixed/adjacent_difference.hpp
index 022d9afa..49624986 100644
--- a/sprout/numeric/fixed/adjacent_difference.hpp
+++ b/sprout/numeric/fixed/adjacent_difference.hpp
@@ -59,7 +59,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			adjacent_difference_impl(
-				InputIterator, InputIterator, Result const& result,
+				InputIterator const&, InputIterator const&, Result const& result,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -133,7 +133,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			adjacent_difference_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
diff --git a/sprout/numeric/fixed/exclusive_scan.hpp b/sprout/numeric/fixed/exclusive_scan.hpp
index ad767372..d7d80ffa 100644
--- a/sprout/numeric/fixed/exclusive_scan.hpp
+++ b/sprout/numeric/fixed/exclusive_scan.hpp
@@ -59,7 +59,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			exclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, T,
+				InputIterator const&, InputIterator const&, Result const& result, T,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -71,7 +71,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			exclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, T init,
+				InputIterator const&, InputIterator const&, Result const& result, T init,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -147,7 +147,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			exclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, T, BinaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, T, BinaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -159,7 +159,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			exclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, T init, BinaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, T init, BinaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
diff --git a/sprout/numeric/fixed/inclusive_scan.hpp b/sprout/numeric/fixed/inclusive_scan.hpp
index 036b9a75..01cb0dc3 100644
--- a/sprout/numeric/fixed/inclusive_scan.hpp
+++ b/sprout/numeric/fixed/inclusive_scan.hpp
@@ -53,7 +53,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			inclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation, T,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation, T,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -65,7 +65,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			inclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation, T init,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation, T init,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
diff --git a/sprout/numeric/fixed/partial_sum.hpp b/sprout/numeric/fixed/partial_sum.hpp
index d6b2a1fc..e5081d02 100644
--- a/sprout/numeric/fixed/partial_sum.hpp
+++ b/sprout/numeric/fixed/partial_sum.hpp
@@ -59,7 +59,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			partial_sum_impl(
-				InputIterator, InputIterator, Result const& result,
+				InputIterator const&, InputIterator const&, Result const& result,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -133,7 +133,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			partial_sum_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
diff --git a/sprout/numeric/fixed/transform_exclusive_scan.hpp b/sprout/numeric/fixed/transform_exclusive_scan.hpp
index 675afb7e..c5eb5d0a 100644
--- a/sprout/numeric/fixed/transform_exclusive_scan.hpp
+++ b/sprout/numeric/fixed/transform_exclusive_scan.hpp
@@ -59,7 +59,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			transform_exclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, T, BinaryOperation, UnaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, T, BinaryOperation, UnaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -71,7 +71,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			transform_exclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, T init, BinaryOperation, UnaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, T init, BinaryOperation, UnaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
diff --git a/sprout/numeric/fixed/transform_inclusive_scan.hpp b/sprout/numeric/fixed/transform_inclusive_scan.hpp
index a831d44e..44d12d8d 100644
--- a/sprout/numeric/fixed/transform_inclusive_scan.hpp
+++ b/sprout/numeric/fixed/transform_inclusive_scan.hpp
@@ -59,7 +59,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			transform_inclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation, UnaryOperation,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation, UnaryOperation,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -102,7 +102,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			transform_inclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation, T,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation, T,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
@@ -114,7 +114,7 @@ namespace sprout {
 				typename sprout::fixed::results::algorithm<Result>::type
 			>::type
 			transform_inclusive_scan_impl(
-				InputIterator, InputIterator, Result const& result, BinaryOperation, T init,
+				InputIterator const&, InputIterator const&, Result const& result, BinaryOperation, T init,
 				typename sprout::container_traits<Result>::size_type
 				)
 			{
diff --git a/testspr/print.hpp b/testspr/print.hpp
index 8eaabfb7..afe82378 100644
--- a/testspr/print.hpp
+++ b/testspr/print.hpp
@@ -138,6 +138,11 @@ namespace testspr {
 	print_typename() {
 		testspr::print_ln(testspr::typename_of<T>());
 	}
+	template<typename T>
+	inline SPROUT_NON_CONSTEXPR void
+	print_typename(T&& t) {
+		testspr::print_ln(testspr::typename_of(std::forward<T>(t)));
+	}
 
 	//
 	// print_type